JP2010069393A - Pneumatic classifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic classifier that can minimize the generation of disturbance of a swirling air stream formed in the inside of a casing, is very simple in structure, and therefore suffers from very little failures and is very low in cost. <P>SOLUTION: The pneumatic classifier includes a hollow rotary shaft 18 which extends along a center line X0 which is a centerline X0 in the inside region of a casing 3 where a swirling air stream A is formed and serves as a center of the swirling air A, is formed throughout the outside and inside of the casing 3, and is rotatable about its own axial line X0 as the center, a dispersion plate 22 that is spacedly opposed to the opening on the inner side of the casing of the rotary shaft 18, a classification blade 29 formed on the external circumference of the rotary shaft 18, and a motor 24 that is formed at the outside of the casing 3 and rotates the rotary shaft 18, wherein a material to be classified is introduced into the inside of the rotary shaft 18 from an opening on the outside of the casing of the rotary shaft 18, and the material is fed from the opening on the inside of the casing of the rotary shaft 18 onto the dispersion plate 22. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air flow classification device that classifies raw materials containing substances having different particle sizes by an air flow such as an air flow.

  For example, according to Non-Patent Document 1, an air classifier called an ultra separator as shown in FIG. 11 is disclosed. In this airflow classifier 101, each chamber of a disperser cell 103, a dispersion chamber cell 104, a classifier cell 105, a classifier intermediate cell 106, and a classifier top cell 107 is provided in this order from the bottom inside a cylindrical casing 102. It is done. A dispersion plate 108 and its driving mechanism 109 are provided in the disperser cell 103, a raw material charging chute 110 is provided in the dispersion chamber cell 104, and a classifying blade is driven in the classifier cell 105. The classifying blade 112 is provided in the classifier intermediate cell 106. An airflow classifier having the same configuration as the airflow classifier 101 is also disclosed in Patent Document 1.

  In this conventional air classifier 101, the dispersion plate 108, the classifying blade 112, and the raw material charging chute 110 must be provided inside the casing 102 in order to function as a classifier. However, in this airflow classifying device 101, the drive mechanisms 109 and 111 for driving them are also provided inside the casing 102, so that the airflow formed inside the casing 102 is disturbed, and the raw material Classification efficiency was bad. Moreover, since the raw material charging chute 110 is inserted into the middle portion of the casing 102 obliquely from the outside to the inside, the airflow is further disturbed, and the classification efficiency of the raw materials is further deteriorated.

  Also, according to Patent Document 2, an airflow classifying device in which a raw material input pipe 230 is provided in the vertical direction, a rotary pipe 240 is provided around the input pipe 230, and a dispersion plate 250 and a classification blade 260 a are provided outside the rotary pipe 240. Is disclosed. According to this airflow classifying device, the drive mechanism for rotationally driving the dispersion plate 250 and the classifying blade 260a is provided outside the casing, and the raw material input pipe 230 is at the center position of the casing, that is, the position where the airflow does not interfere with the flow. Therefore, a relatively stable swirling airflow can be formed in the casing.

  According to Patent Document 3, a dispersion plate 47 is supported by a solid rotating shaft 44 extending in the vertical direction, and a raw material supply chute 37 is provided around the rotating shaft 44, An airflow classification device provided with classification blades 56 is disclosed. According to this airflow classifying device, a drive mechanism for rotationally driving the dispersion plate 47 and the classifying blades 56 is provided outside the casing, and the raw material supply chute 37 is located at the center of the casing, that is, a position that does not disturb the flow of the airflow. Therefore, a relatively stable swirling airflow can be formed in the casing.

Japanese Examined Patent Publication No. 44-32554 (pages 1 and 2, attached figure) Japanese Patent Laid-Open No. 05-285412 (pages 3 to 4, FIG. 1) JP 2002-119920 A (pages 4 to 8, FIG. 1) Classifier technical manual, 1st edition, 1st printing, 272-275 pages, published on May 15, 1978, edited by Japan Powder Industry Association, published by Industrial Technology Center Co., Ltd.,

  In the airflow classifying devices disclosed in Patent Document 2 and Patent Document 3, the mechanism for driving the dispersion plate and the classifying blade and the structure for supplying the raw material are intertwined in a complicated manner. There was a problem that the airflow is likely to be disturbed. In addition, since the structure is complicated, there is a problem that the parts cost and the manufacturing cost become very high. Further, since the structure is complicated, it is difficult to achieve a balance at the time of rotation, and there is a possibility of a decrease in classification efficiency and damage to equipment due to uneven rotation and generation of vibration during rotation.

  The present invention has been made in view of the above-described problems, and can suppress the occurrence of turbulence in the swirling airflow formed inside the casing as much as possible, and thus can obtain high classification efficiency. An object of the present invention is to provide an air classifier that can perform the above. It is another object of the present invention to provide an air classifier that has a very simple configuration and therefore has few failures and is very inexpensive.

  The present invention has been made to achieve the above-described object, and includes a hollow casing, an airflow inlet provided in the casing and introducing an airflow that becomes a swirling airflow in the casing, and the casing A center line of the inner region of the swirl airflow, and extends along or parallel to the center line of the swirling airflow, and is provided between the outside and the inside of the casing and is centered on its own axis. A hollow rotating shaft that is rotatable as a rotating plate, a dispersion plate that is provided at an opening end portion of the rotating shaft on the inner side of the casing and is opposed to the opening with an interval, and a direction in which the airflow flows Classification blades provided on the downstream side of the dispersion plate and provided on the outer peripheral surface of the rotating shaft and extending in a direction perpendicular to the center line of the rotating shaft, and a direction in which the airflow flows The airflow outlet provided on the downstream side of the classification blade and the rotary shaft driving means provided on the outside of the casing for rotating the rotary shaft, and the material to be classified is in the rotary shaft It is introduced into the inside of the rotating shaft from the opening on the outer side of the casing, and the material is supplied onto the dispersion plate from the opening on the inner side of the casing on the rotating shaft.

  According to the airflow classifying device of the present invention, the rotating shaft functions as an introduction tube for introducing the material into the casing, and also functions as a driving shaft for rotating the dispersion plate and the classification blade. And the rotating shaft drive means for driving a rotating shaft is provided in the exterior of the casing. As a result of the combination of these structural requirements, the interior space of the casing is a clean single space in which unnecessary components are not present, so that a clean and stable swirling airflow can be formed inside the casing. Therefore, the classification efficiency (that is, the ratio of the product material having a desired particle diameter obtained from the input raw material in one classification operation) can be increased.

  Furthermore, in the airflow classifying device of the present invention, the rotating shaft is also used as the drive shaft for the dispersion plate and the classifying blade and the input pipe for the raw material. For this reason, the structure around the rotation axis is very simple. For this reason, the probability that a failure will occur in that portion is greatly reduced. Further, since the structure is simple, the swirling airflow is maintained in a clean state without being disturbed, and the classification efficiency can be maintained high.

  By the way, a water-washing or wet classifying device for washing fine powder contained in a material with water is already known. In this water-washing type classification device, each of the cleaning, drying, and drainage treatments must be performed, so that a treatment device for these treatments is necessary, and the equipment cost and running cost are extremely high. . On the other hand, the airflow classifier of the present invention has a very simple configuration and is dry and does not require any washing process, so that the cost can be greatly reduced as compared with the water classifier.

  Further, the airflow classifying device of the present invention has a structure around the raw material input pipe and a drive mechanism such as a dispersion plate as compared with the airflow classifying devices disclosed in Japanese Patent Application Laid-Open Nos. 5-285512 and 2002-119920. The structure of the periphery of the slab is remarkably simple, and the cost can be greatly reduced and the occurrence of failure can be greatly reduced.

  Next, in the airflow classifying device according to the present invention, it is desirable that the rotation direction of the rotation shaft is the same direction as the swirl direction of the swirling airflow. By rotating the rotating shaft, it is possible to apply a centrifugal force to the material introduced into the casing by the rotating shaft in advance, thereby providing appropriate dispersion. Then, by setting the rotation direction of the rotating shaft to be the same as the swirling direction of the swirling airflow, the material released into the casing can be smoothly put on the swirling airflow.

  Next, in the airflow classifying device according to the present invention, the classification blade has a plurality of blade members provided around the rotation shaft, and the plurality of blade members are arranged in a circumferential direction around the rotation shaft. The blade members are spaced apart from each other, and each of the plurality of blade members is rotatable about an axis parallel to the center axis of the rotation shaft, and each blade member is perpendicular to the center axis of the rotation shaft. It is desirable to extend in the direction.

  Compared to the classification blades disclosed in Patent Document 4 (Japanese Patent Laid-Open No. 05-285212) and Patent Document 5 (Japanese Patent Laid-Open No. 2002-119920), the classification blade having this configuration is simple and small in size. It is. Therefore, the possibility of causing turbulence in the swirling airflow inside the casing can be greatly reduced.

  Next, in the airflow classifying apparatus according to the present invention, the casing has a cylindrical shape with a circular cross section extending in the vertical direction, and a coarse outlet is provided in a lower portion of the casing, and the coarse outlet is provided on the coarse outlet. The airflow inlet is provided, the dispersion plate is provided on the airflow inlet, the classification blade is provided on the dispersion plate, the airflow discharge port is provided on the classification blade, It is desirable that the airflow outlet is a fine powder outlet. According to this configuration, the air classifier according to the present invention can be practically realized.

  Next, in the airflow classifying device according to the present invention, a hopper is provided in communication with the opening on the outer side of the casing on the rotating shaft, and the hopper has a smaller cross-sectional area as the opening side is narrower and away from the opening. Preferably, the hopper has a conical shape, and the hopper is held in an immobile state regardless of the rotation of the rotating shaft. With this configuration, the material can be easily and stably charged into the rotating shaft.

  Next, it is preferable that the airflow classifying device according to the present invention further includes a high-temperature airflow supply unit that supplies a high-temperature airflow to the inside of the casing through the airflow inlet. According to this configuration, the swirling airflow formed in the casing can be a high-temperature airflow. If the swirl airflow becomes high temperature, the fine powder contained in the material can be dried during the classification process, and the moisture content of the fine powder can be reduced. This means, for example, that a fine powder product that is required to have a low water content such as tancal, that is, a filler, can be easily and directly produced, which is very effective in practice. .

  According to the airflow classifying device according to the present invention, the rotating shaft functions as an introduction tube for introducing the material into the casing, and also functions as a driving shaft for rotating the dispersion plate and the classification blade. Further, the rotating shaft driving means for driving the rotating shaft is provided outside the casing. As a result of the combination of these structural requirements, the interior space of the casing is a clean single space in which unnecessary components are not present, so that a clean and stable swirling airflow can be formed inside the casing. Therefore, classification efficiency can be increased.

  Furthermore, in the airflow classifying device of the present invention, the rotating shaft is also used as the drive shaft for the dispersion plate and the classifying blade and the input pipe for the raw material. For this reason, the structure around the rotation axis is very simple. For this reason, the probability that a failure will occur in that portion is greatly reduced. Further, since the structure is simple, the swirling airflow is maintained in a clean state without being disturbed, and the classification efficiency can be maintained high.

  Further, the airflow classifying apparatus of the present invention is very simple in construction, and is dry and does not require any washing process, so that the cost can be greatly reduced as compared with the water classifying apparatus.

  Further, the airflow classifying device of the present invention has a structure around the raw material input pipe and a driving mechanism such as a dispersion plate, as compared with the airflow classifying devices disclosed in Japanese Patent Application Laid-Open Nos. H5-285412 and 2002-119920. The structure of the periphery of the slab is remarkably simple, and the cost can be greatly reduced and the occurrence of failure can be greatly reduced.

(First embodiment)
Hereinafter, an airflow classification device according to the present invention will be described based on embodiments. Of course, the present invention is not limited to this embodiment. In the following description, the drawings are referred to. In the drawings, the components may be shown in different ratios from the actual ones in order to show the characteristic parts in an easily understandable manner.

  FIG. 1 shows an embodiment of an air classifier according to the present invention. FIG. 2 shows the overall side structure of an airflow classification system in which the airflow classification device is used. FIG. 3 shows a planar structure of the airflow classification system.

  In FIG. 1, the airflow classifier 1 has a casing 3 that is supported by a machine base 2 and extends in the vertical direction. The casing 3 is made of steel plates having different cross-sectional diameters and is formed by joining cylindrical or conical cylindrical members. The casing 3 is hollow, that is, the inside is a space. The cross section of the internal space is circular, and the central axis X0 of the internal space extends in the vertical direction. In addition, the material of the various components demonstrated from now on is a steel material, unless specifically limited.

  The lower end of the casing 3 is an opening 4 having a small diameter. The opening 4 functions as a coarse powder outlet for discharging coarse powder contained in the raw material, for example, powder having a particle size of 0.15 mm or more. A belt conveyor 7 serving as a conveying means for conveying powder is provided below the coarse powder outlet 4.

  The top end of the casing 3 is covered with a steel top plate 5. An opening 6 is provided at an appropriate place of the top 5, that is, at the place indicated by a broken line on the back side in FIG. The opening 6 is an opening through which a swirling airflow described later in the casing 3 is exhausted, and functions as a fine powder discharge port for discharging fine powder contained in the raw material, for example, powder of 0.15 mm or less. A powder transport pipe 8 is joined to the fine powder outlet 6.

  A portion of the casing 3 adjacent to the coarse powder outlet 4 is an inverted conical powder recovery unit 9. A portion adjacent to the powder recovery unit 9 is provided with a ring-shaped, that is, ring-shaped opening 11. The opening 11 functions as an air flow inlet for introducing an air flow into the casing 3. As shown in FIG. 3, a ring-shaped airflow introduction pipe 12 is provided around the ring-shaped opening 11, and between the airflow introduction pipe 12 and the internal space of the casing 3, as shown in FIG. 5. In addition, a plurality of airflow guide vanes 13 are provided. In addition, an airflow conveyance pipe 14 is joined to an appropriate position of the airflow introduction pipe 12.

  A main fan 16 that is an airflow generation source is provided at an appropriate position of the airflow conveyance pipe 14, in this embodiment, at an end of the airflow conveyance pipe 14. The main fan 16 has a fan that rotates at a predetermined speed, that is, blades, and generates airflow by the rotation of the fan. This airflow is conveyed to the airflow introduction pipe 12 through the airflow conveyance pipe 14 and further introduced into the casing 3 by the airflow guide vanes 13 of FIGS. 1 and 5. A damper 20a as a flow rate adjuster is provided in the vicinity of the air flow outlet of the main fan 16.

  A dust collector 46 having a fan is provided at a position downstream of the main fan 16 with respect to the direction in which the airflow flows. Dust and the like are sucked from the airflow conveyance pipe 14 by the intake of the fan, and the dust and the like are collected by the dust collector 46. Due to the intake action of the fan, the inside of the casing 3 is set to a negative pressure, that is, a pressure lower than the outside. Reference numeral 20 b denotes a damper provided in the airflow conveyance pipe that connects the airflow conveyance pipe 14 and the dust collector 46.

  The airflow introduced into the casing 3 by the action of the airflow introduction pipe 12 and the airflow guide vane 13 becomes a swirling airflow, that is, a vortex airflow, that is, a spiral airflow in FIG. Thus, the inside of the casing 3 extending in the vertical direction is raised. Note that the symbol A schematically shows the flow of the swirling airflow so as to help understanding, and does not necessarily indicate the actual airflow accurately. The center of the swirling airflow coincides with the central axis X0 of the casing 3. The whirling airflow inside the casing 3 is discharged to the powder conveying tube 8 through the opening 6 provided in the top plate 5.

  A bracket 17 extending upward is provided on the outer surface of the top plate 5, and a rotating shaft 18 is supported by the bracket 17. The rotary shaft 18 can be rotated around its own axis by a bearing 19, so-called axial rotation. The rotation axis of the rotation shaft 18 coincides with the center axis X0 of the internal space of the casing 3, that is, the center line of the swirling airflow. In the following description, the center axis of the internal space of the casing 3, the center line of the swirling airflow, and the rotation axis of the rotary shaft 18 may be respectively indicated by a common symbol X0. Note that the center axis of the internal space of the casing 3, the center line of the swirling airflow, and the rotation axis of the rotary shaft 18 may not match each other.

  The rotating shaft 18 has a hollow cylindrical shape, and a disc-shaped dispersion plate 22 is rotated by a plurality of, for example, four ribs 21 (the illustration of one rib on the near side is omitted) at the lower end thereof. 18 and are fixed so as to be integrated. A hopper 23 is provided at the upper end of the rotating shaft 18 for receiving and storing raw materials to be classified. The hopper 23 is fixed in a position immovable and non-rotatable state. The hopper 23 and the rotary shaft 18 communicate spatially, and the hopper 23 does not prevent the rotation of the rotary shaft 18. For example, the tip of the hopper 23 and the tip of the rotating shaft 18 face each other with a slight gap. Of course, this gap is small enough to prevent the raw material from leaking out.

  Classification blades 29 are attached to the outer peripheral surface of the rotating shaft 18 existing in the internal space of the casing 3. FIG. 6 shows a planar structure of the classification blade 29, and FIG. 7 shows a side sectional structure of the classification blade 29. As shown in these drawings, two disc-shaped support members 31a and 31b are fixed on the outer peripheral surface of the rotary shaft 18 so as to be immovable at intervals along the central axis X0. This fixing method may be welding, bolt fixing, or any other method. A plurality of blade members 32 are attached to the support members 31a and 31b so as to be rotatable about the axis X1 on the outer peripheral edges of the support members 31a and 31b. These axes X1 are set in parallel with the central axis X0 of the rotating shaft 18. Each blade member 32 is formed as a generally rectangular plate, and the outer peripheral tip is thin and sharp.

  When the rotating shaft 18 is stationary, each blade member 32 is in a state where it can freely rotate about the axis X1, and each can face a disordered direction. When the rotating shaft 18 is rotating, the blade members 32 are arranged radially at regular intervals by centrifugal force as shown in FIG. In FIG. 1, the swirling airflow in the casing 3 passes between the blade members 32 and is discharged from the discharge opening 6. When the raw material is contained in the airflow, the fine powder having a small particle diameter passes between the blade members 32 and is discharged from the fine powder opening 6. On the other hand, the coarse powder having a large particle diameter is hit by the blade member 32 and falls to the coarse powder opening 4.

  An electric motor 24 that is a drive source for rotating the rotary shaft 18 is fixed to the bracket 17. A pulley 26 is attached to the output shaft of the motor 24. A pulley 27 is attached on the outer peripheral surface of the rotating shaft 18 facing the pulley 26. A belt 28 is stretched between the pulleys 26 and 27. When the motor 24 is actuated to rotate its output shaft, the rotation is transmitted via the belt 28, and the rotation shaft 18 rotates about its own central axis X0.

  The diameter of the internal space (the space in which the swirling airflow is formed) in the lower part of the casing 3 than the dispersion plate 22 is about 1410 mm. And the internal diameter of the rotating shaft 18 is about 130 mm, and the external shape is about 165 mm. That is, the inner diameter of the rotating shaft 18 is about 9.2% with respect to the diameter of the casing internal space. According to the experiments by the inventors, it has been found that the inner diameter of the rotating shaft 18 is preferably about 9% to 10% with respect to the inner diameter of the internal space of the casing.

Hereinafter, the operation | movement is demonstrated regarding the airflow classification apparatus 1 which consists of the said structure.
When the main fan 16 operates in FIG. 2, the airflow is introduced into the casing 3 through the airflow conveyance pipe 14 and the airflow introduction pipe 12, and is located at the top of the casing 3 from the airflow introduction opening 11 inside the casing 3 in FIG. 1. A swirling airflow, a spiral airflow, or a spiral airflow is formed between the airflow discharge openings 6.

  Simultaneously with the above-described swirl airflow forming process, the motor 24 is operated to rotate the rotating shaft 18. By this rotation, the dispersion plate 22 and the classification blade 29 rotate together with the rotation shaft 18. The rotation direction of the rotating shaft 18, that is, the rotation direction of the dispersion plate 22 and the classification blade 29 is set to the same direction as the swirling direction of the swirling airflow formed in the casing 3. Thereby, it can prevent that the raw material disperse | distributed by the dispersion | distribution board 22 is disturbed more than necessary by a swirl | vortex rising airflow, and can perform the stable classification process.

  As described above, a swirling airflow is formed in the casing 3 around the axis X0, and when the rotary shaft 18, the dispersion plate 22 and the classification blade 29 are rotated around the axis X0, the raw material, for example, Limestone obtained by grinding is charged, that is, supplied. The input limestone raw material includes fine powder having a particle size of 0.15 mm or less and coarse powder having a particle size of 0.15 mm or more. In this embodiment, coarse powder shall be collect | recovered as crushed sand which is a product.

  The raw material thrown into the hopper 23 passes through the inside of the rotating shaft 18 and falls onto the dispersion plate 22. The dropped raw material is discharged from the dispersion plate 22 in the horizontal direction by centrifugal force and dispersed in the casing 3. Among the dispersed raw materials, the powder having a large particle size and heavy falls without getting on the swirling airflow, and is discharged from the coarse powder collection opening 4 at the bottom of the casing 3 to the outside as crushed sand as a product. On the other hand, a powder having a small particle size and a light weight among the raw materials rises in a swirling updraft, passes through the classification blade 29 and is discharged from the opening 6 to the outside.

  Coarse powders are also present in the raw materials that have been swirling and rising. When this coarse powder is carried on the swirling airflow and carried to the classification blade 29, it is struck by the blade member 32 constituting the classification blade 29 and falls, and the product is crushed from the coarse powder collection opening 4 at the lower portion of the casing 3. To be recovered.

  In the present embodiment, the boundary particle diameter between the coarse powder and the fine powder is set to 0.15 mm, but this can be changed by changing the rotation speed of the classification blade 29 and hence the rotation speed of the rotary shaft 18. For example, when the rotational speed of the classification blade 29 is increased, the boundary particle size can be reduced, that is, the particle size of the fine powder discharged from the fine powder opening 6 can be reduced.

  In the airflow classification device 1 according to the present embodiment, the rotary shaft 18 functions as an introduction pipe for introducing the raw material M into the casing 3 and as a drive shaft for rotating the dispersion plate 22 and the classification blade 29. It is functioning. A motor 24 that is a drive source of the rotating shaft 18 is installed outside the casing 3. As a result of these configurations, the internal space of the casing 3 is a clean single space in which unnecessary components are not present. Therefore, a clean and stable whirling airflow can be formed inside the casing 3. Therefore, classification efficiency can be increased. That is, a large amount of product crushed sand having a desired particle diameter can be obtained from raw materials by one classification process.

  Further, in the present embodiment, the rotary shaft 18 is also used as a drive shaft for the dispersion plate 22 and the classification blade 29 and as a raw material input pipe. For this reason, the structure around the rotating shaft 18 is very simple. For this reason, the probability that a failure will occur in that portion is greatly reduced. In addition, since the structure is simple, the swirling airflow is maintained in a clean state without being disturbed, and the classification efficiency can be maintained high. Furthermore, there is no rotation unevenness or vibration on the rotating shaft 18, so that stable classification processing can be performed and damage to the equipment can be prevented.

  Further, since the rotary shaft 18 that functions as the raw material input pipe rotates in the same direction as the swirling direction of the swirling airflow, the raw material is subjected to preliminary dispersion treatment by the rotary shaft 19 in advance before dropping onto the dispersion plate 22. Therefore, the classification efficiency can be increased for the reason.

  By the way, a water-washing or wet classifying device for washing fine powder contained in raw materials with water is already known. In this water-washing type classification device, each of the cleaning, drying, and drainage treatments must be performed, so that a treatment device for these treatments is necessary, and the equipment cost and running cost are extremely high. . On the other hand, the airflow classifying device of the present embodiment is very simple in configuration, and is dry and does not require any washing process. Therefore, the cost can be greatly reduced as compared with the water-washing classifier.

  In addition, the airflow classifying device of the present embodiment is closer to the periphery of the drive mechanism such as the raw material input pipe and the dispersion plate than the airflow classifying devices disclosed in Japanese Patent Laid-Open Nos. 5-2851212 and 2002-119920. The structure is remarkably simple, and the cost can be greatly reduced, and the occurrence of failure can be greatly reduced.

(Use example of air classifier)
Next, an airflow classification system that is one example of use of the airflow classification device 1 of FIG. 1 will be described with reference to FIGS. 2 is a side view of the airflow classification system, FIG. 3 is a plan view of the airflow classification system, and FIG. 4 is a block diagram of the airflow classification system.

  The airflow classification system 41 includes an airflow classification device 1 shown in FIG. 1, a raw material supply belt conveyor 42 that supplies raw materials to the airflow classification device 1, and a fine powder extending from the top of the casing 3 of the airflow classification device 1. A cyclone 43 connected to the conveying pipe 8, a dust belt conveyor 44 provided at a position below the powder discharge port at the lower end of the cyclone 43, a connecting pipe 45 for connecting the top of the cyclone 43 and the main fan 16; Have In FIG. 2, a raw material hopper 47 is provided at the conveyance start end of the raw material feed belt conveyor 42, and raw materials to be classified are stored in the hopper 47.

  The length L1 of the raw material supply belt conveyor 42 is, for example, 18 m (meters). The body height H1 from the facility facility surface (for example, the ground) to the upper end of the hopper 23 of the airflow classifying device 1 is, for example, 5.6 m (meters).

  When each device constituting the airflow classification system 41 is set in an operating state, an appropriate amount of raw material is supplied from the hopper 47 to the raw material supply belt conveyor 42 in FIG. 2, and the raw material is supplied to the airflow classification device 1 by the belt conveyor 42. To the hopper 23. Then, the airflow classification process described with reference to FIG. 1 is executed, and coarse powder as a product, that is, crushed sand, is taken out from the coarse powder discharge opening 4 at the lower end of the casing 3 and collected on the belt conveyor 7.

  On the other hand, fine powder is taken out from the fine powder discharge opening 6 at the upper end of the casing 3 and conveyed to the cyclone 43 by the conveyance pipe 8. The fine powder is discharged from the lower end opening of the cyclone 43 and collected on the dust belt conveyor 44. The collected fine powder is used as, for example, tancal according to demand. The airflow returns from the cyclone 43 to the main fan 16 through the connecting pipe 45.

(Second Embodiment)
FIG. 8 shows another embodiment of the airflow classification device according to the present invention and a side structure of an airflow classification system using the airflow classification device. FIG. 9 shows the planar structure of the air flow classification device and the air flow classification system. FIG. 10 shows a block diagram of the air flow classification system.

  The airflow classifying device 51 included in the airflow classifying system 61 according to this embodiment is different from the airflow classifying device 1 shown in FIGS. 1 and 2 in that the main fan 16 has the flow direction of the airflow sent from the main fan 16. The hot air supply device 52 is provided at a downstream position, that is, a downstream position of the dust collector 46 in the present embodiment. The rest of the configuration is the same as that of the airflow classifier 1, and the same components are denoted by the same reference numerals, and description thereof is omitted.

  The hot air supply device 52 includes, for example, a device that generates heat, such as a heater, and a device that flows the generated heat on an airflow. The hot air supply device 52 supplies hot air, that is, a high-temperature air flow, into the air flow conveying pipe 14.

  The supplied hot air is introduced into the casing 3 through the annular airflow introduction pipe 12 together with the airflow sent from the main fan 16, and becomes a hot swirl airflow A in FIG. It becomes. The raw material supplied from the hopper 23, supplied to the inside of the casing 3 through the inside of the rotary shaft 18 and dispersed by the dispersion plate 22 is classified into coarse powder and fine powder while flowing on the hot swirling airflow A. Is done.

  According to this embodiment, the classification process can be executed while the raw material is dried by the high-temperature swirling airflow A. As a result, the moisture content of the fine powder taken out from the fine powder discharge opening 6 at the upper part of the casing 3 in FIG. 1 can be efficiently reduced. This is very advantageous when it is necessary to ship a fine powder that is required to have a low water content as a product, for example, when making a fine powder that is used as a filler, that is, a filler, such as Tankar. It is.

(Other embodiments)
The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the invention described in the claims. For example, the raw material is not limited to limestone, and any ore can be selected as necessary. In addition, in FIG. 1, the shape of the casing 3 is not limited to the illustrated one, and can be an arbitrary shape. Further, the configuration for rotatably supporting the rotary shaft 18 is not limited to the structure shown in the figure.

Next, a first experimental example will be described. The experimental conditions are as shown in test numbers 1 to 4 in Table 1. Table 1 is displayed in two columns. The conditions in Table 1 are as follows.
(1) Four experiments indicated by test numbers 1 to 4 were performed. Test number 5 is a comparative example using a conventional airflow classifier.

(2) In each experiment of number 1-4, the apparatus which does not use the airflow classification apparatus and airflow classification system shown in FIGS. 1-4, ie, a hot-air supply apparatus, was used.
(3) In each experiment of Nos. 1 to 4, dolomite having a particle size of 2.5 mm or less was applied as a raw material.

(4) “Feed” in “Processing / Production Volume (t / h)” in Table 1 indicates the amount of raw material supplied to the hopper 23 in FIG. 1, and “product” was discharged from the coarse powder discharge opening 4. The amount of coarse powder as a product, and “filler” indicates the amount of fine powder discharged from the fine powder discharge opening 6.
(5) “Classifier (rpm)” is the rotational speed of the rotary shaft 18 of FIG.

(6) “Air volume (m ³ / min)” indicates the amount of air flow sent into the casing 3 by the main fan 16 of FIG.
(7) “Raw stone” of “Moisture (%)” indicates the amount of moisture contained in the raw material, “Product” indicates the amount of moisture contained in the coarse powder as a product discharged from the coarse powder discharge opening 4, “Filler” indicates the amount of water contained in the fine powder discharged from the fine powder discharge opening 6.

(8) “Crumbled sand (FM value)” is an FM value of coarse powder as a product discharged from the coarse powder discharge opening 4.
(9) “Raw stone” in “−0.15 mm portion (%)” is the amount of fine powder having a particle size of 0.15 mm or less contained in the raw material. The “finished product” is the abundance of fine powder having a particle size of 0.15 mm or less contained in the coarse powder as a product discharged from the coarse powder discharge opening 4. “Filler” is the amount of fine powder having a particle diameter of 0.15 mm or less contained in fine powder discharged from the fine powder discharge opening 6.

  (10) “Raw stone” in “−0.075 mm portion (%)” is the amount of fine powder having a particle size of 0.075 mm or less contained in the raw material. “Product” is the abundance of fine powder having a particle size of 0.075 mm or less contained in the coarse powder as a product discharged from the coarse powder discharge opening 4. “Filler” is the amount of fine powder having a particle size of 0.075 mm or less contained in fine powder discharged from the fine powder discharge opening 6.

[Comparative Example 1]
Next, a classification experiment was performed using a conventional airflow classification device of another company. The conditions are as shown in test number 5 in Table 1.
[Comparison]
Comparison of Experimental Example 1 (No. 1 to 4) and Comparative Example 1 (No. 5) in Table 1 reveals the following. That is, as can be seen from the product yield section, the yield was greatly improved by using the airflow classifier of the present invention. That is, the classification efficiency was greatly improved.

  Moreover, according to the airflow classifying device of the present invention, the rotational speed of the classifying blades and the like can be kept low, so that stable operation can be performed while suppressing failure.

  Also, as can be seen from the “Filler” column in the “−0.15 mm portion (%)” and “−0.075 mm portion (%)” sections, the amount of fine powder contained in the filler is increased. I was able to. In other words, it was found that the classification efficiency was improved.

Next, a second experimental example will be described. The experimental conditions are as shown in Test Nos. 1 and 2 in Table 2. Table 2 is displayed over two columns. The conditions in Table 2 are as follows.
(1) Two experiments indicated by test numbers 1 and 2 were performed. The experiment of No. 1 is performed under room temperature conditions without operating the hot air supply device 52 in the airflow classifying device and the airflow classifying system shown in FIGS. The room temperature at this time was 30 ° C. In the experiment of No. 2, classification was performed in a state where the hot air drying device 52 was operated in the airflow classifying device and the airflow classifying system shown in FIGS.

(2) In each experiment of Nos. 1 and 2, a filler, that is, a fine powder having a particle size of 0.15 mm or less was applied as a raw material.
(3) “Feed” in “Processing / Production Volume (t / h)” in Table 2 indicates the amount of raw material supplied to the hopper 23 in FIG. 1, and “Product” was discharged from the coarse powder discharge opening 4. The amount of coarse powder as a product, and “filler” indicates the amount of fine powder discharged from the fine powder discharge opening 6.

(4) “Classifier (rpm)” is the rotational speed of the rotary shaft 18 of FIG.
(5) “In the classifier” at “temperature ° C.” is the temperature in the classifier, “product” is the temperature of the coarse powder discharged from the coarse powder discharge opening 4, and “filler” is the fine powder discharge opening 6. It is the temperature of the fine powder discharged from.

(6) “Air volume (m ³ / min)” indicates the amount of air flow sent into the casing 3 by the main fan 16 of FIG.
(7) “Raw stone” of “Moisture (%)” indicates the amount of moisture contained in the raw material, “Product” indicates the amount of moisture contained in the coarse powder as a product discharged from the coarse powder discharge opening 4, “Filler” indicates the amount of water contained in the fine powder discharged from the fine powder discharge opening 6.

  As a result of the experiment, the following was found. That is, when the air flow classification is performed by generating a swirling air flow at normal temperature inside the casing 3 without operating the hot air supply device 52, it is shown in the “Filler” column of “Moisture (%)” of the test number 1. Thus, the water content contained in the filler (ie fine powder) was 0.59%. On the other hand, when the hot air supply device 52 is operated to generate a hot swirling airflow in the casing 3 and airflow classification is performed, as shown in the column of “Filler” of “Moisture (%)” of Test No. 2 In addition, the amount of water contained in the filler (ie fine powder) decreased to 0.13%. In addition, the temperature in the casing 3 at this time was 50 degreeC. The temperature of the coarse powder taken out from the coarse powder discharge opening 4 at the lower end of the casing 3 in FIG. 1 was 40 ° C., and the temperature of the fine powder taken out from the fine powder discharge opening 6 at the upper end was 41 ° C. .

A filler having a water content of 0.13% is a filler that can be used practically without any problem. Thus, if the airflow classifying device according to the present invention in which a swirling airflow for high temperature classification is formed in the casing 3, crushed sand (that is, coarse powder) as a product can be efficiently generated, and A fine powder in a dry state having a low water content can be obtained at the same time, and this fine powder can be suitably used, for example, as a tancal, that is, a filler. Thus, it became possible to simultaneously produce crushed sand and filler as a product.

Table 1

Table 2

It is side surface sectional drawing which shows one Embodiment of the airflow classification apparatus which concerns on this invention. It is a front view which shows one Embodiment of the airflow classification system using the airflow classification apparatus of FIG. It is a top view of the airflow classification system of FIG. It is a block diagram of the airflow classification system of FIG. It is a plane sectional view showing the principal part of the air current classification device of FIG. It is a top view which shows the other main part of the airflow classification apparatus of FIG. It is side surface sectional drawing of the member of FIG. It is side surface sectional drawing of the airflow classification system containing other embodiment of the airflow classification apparatus which concerns on this invention. It is a top view of the airflow classification system of FIG. It is a block diagram of the airflow classification system of FIG. It is side surface sectional drawing of an example of the conventional airflow classification apparatus.

Explanation of symbols

1. 1. Airflow classifier, Machine base, 3. Casing, 4. 4. Coarse powder discharge opening, Top board,
6). 6. Fine powder discharge opening, Belt conveyor, 8. 8. Fine powder conveying tube, Powder recovery unit,
11. Opening, 12. 12. air flow introduction pipe, Airflow guide vanes, 14. Airflow conveying pipe,
15. Feed controller connection port, 16. Main fan, 17. bracket,
18. Rotation axis, 19. Bearings, 20a, 20b. Damper, 21. Ribs, 22. Dispersion plate,
23. Hopper, 24. Electric motor, 26. Pulley, 27. Pulley, 28. belt,
29. Classification blade, 31a, 31b. Support member, 32. Blade member,
41. Airflow classification system, 42. Raw material feed belt conveyor, 43. Cyclone,
44. Dust belt conveyor, 45. Connecting pipe, 46. Dust collector 47. Raw material hopper,
51. Airflow classifier, 52. Hot air supply device

Claims (6)

A hollow casing;
An air flow inlet that is provided in the casing and introduces an air current that is a swirling air flow in the casing;
A central line of the inner region of the casing, which extends along or parallel to the central line of the swirling airflow, and is provided across the outside and the inside of the casing; A hollow rotating shaft that is rotatable about the axis of
A dispersion plate that is provided at an opening end portion on the inner side of the casing in the rotating shaft and is opposed to the opening at an interval;
Classification blades provided on the downstream side of the dispersion plate with respect to the flow direction of the airflow, provided on the outer peripheral surface of the rotating shaft, and extending in a direction perpendicular to the center line of the rotating shaft;
An air flow outlet provided on the downstream side of the classification blade with respect to the flow direction of the air flow;
A rotating shaft driving means that is provided outside the casing and rotates the rotating shaft;
The material to be classified is introduced into the inside of the rotating shaft from the opening on the outer side of the casing on the rotating shaft, and the material is supplied onto the dispersion plate from the opening on the inner side of the casing on the rotating shaft. Airflow classifier characterized by.   The airflow classification device according to claim 1, wherein the rotation direction of the rotating shaft is the same direction as the swirling direction of the swirling airflow. In the air classifier according to claim 1 or 2,
The classification blade has a plurality of blade members provided around the rotation shaft,
The plurality of blade members are provided to be spaced from each other in a circumferential direction around the rotation axis,
Each of the plurality of blade members is rotatable about an axis parallel to the central axis of the rotation axis,
Each blade member extends in a direction perpendicular to the central axis of the rotating shaft. In the air classifier according to claim 1 to 3,
The casing has a cylindrical shape with a circular cross section extending in the vertical direction,
A coarse outlet is provided at the bottom of the casing,
The air flow inlet is provided on the coarse particle outlet,
The dispersion plate is provided on the air flow inlet,
The classification blade is provided on the dispersion plate,
An airflow classifying device, wherein the airflow discharge port is provided on the classification blade, and the airflow discharge port becomes a fine powder discharge port. In the airflow classification device according to any one of claims 1 to 4,
A hopper is provided in communication with the opening on the outer side of the casing in the rotating shaft,
The hopper has a conical shape in which the opening side is narrow and the cross-sectional area increases as the distance from the opening increases.
The air flow classification device according to claim 1, wherein the hopper is held in an immobile state regardless of the rotation of the rotating shaft. In the airflow classification device according to any one of claims 1 to 5,
An airflow classifying device comprising high-temperature airflow supply means for supplying a high-temperature airflow into the casing through the airflow inlet.

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